If you happen to live in Germany and would like to try the new PS4 feature; Share Play, you can only invite or be invited by other Germans.
This particular detail was not known when Sony talked about the service recently. It has however been discovered by Redditor Alkanida when he received an invitation from his friend in the UK to try out FIFA 15.
As you can see, the message indicates that the feature can only be used in certain countries. Which in this case is only from users in Germany.
The PlayStation FAQ website reveals even more details (via NeoGAF). Besides confirming the above detail, the FAQ adds that any German user getting invited to a game has to put in their ID number if the game is rated 16+ or higher.
Furthermore, a user cannot be invited to play a game that’s not available in their region’s PSN store.